<!--
 * @Descripttion: 局部水印组件
 * @version: 1.1
 * @Author: sakuya
 * @Date: 2021年12月18日12:16:16
 * @LastEditors: Xujianchen
 * @LastEditTime: 2023-03-18 13:14:19
-->

<template>
  <div ref="scWaterMark" class="sc-water-mark">
    <slot></slot>
  </div>
</template>

<script>
export default {
  props: {
    text: { type: String, required: true, default: '' },
    subtext: { type: String, default: '' },
    color: { type: String, default: 'rgba(128,128,128,0.2)' },
  },
  data() {
    return {}
  },
  mounted() {
    this.create()
  },
  methods: {
    create() {
      this.clear()
      //创建画板
      var canvas = document.createElement('canvas')
      canvas.width = 150
      canvas.height = 150
      canvas.style.display = 'none'
      //绘制文字
      var text = canvas.getContext('2d')
      text.rotate((-45 * Math.PI) / 180)
      text.translate(-75, 25)
      text.fillStyle = this.color
      text.font = 'bold 20px SimHei'
      text.textAlign = 'center'
      text.fillText(this.text, canvas.width / 2, canvas.height / 2)
      text.font = '14px Microsoft YaHei'
      text.fillText(this.subtext, canvas.width / 2, canvas.height / 2 + 20)
      //创建水印容器
      var watermark = document.createElement('div')
      watermark.setAttribute('class', 'watermark')
      const styleStr = `position:absolute;top:0;left:0;right:0;bottom:0;z-index:99;pointer-events:none;background-repeat:repeat;background-image:url('${canvas.toDataURL('image/png')}');`
      watermark.setAttribute('style', styleStr)
      this.$refs.scWaterMark.appendChild(watermark)
    },
    clear() {
      var wmDom = this.$refs.scWaterMark.querySelector('.watermark')
      wmDom && wmDom.remove()
    },
  },
}
</script>

<style scoped>
.sc-water-mark {
  position: relative;
  display: inherit;
  width: 100%;
  height: 100%;
}
</style>
